To access the web cams on iBooks from another workstation running OS X. So effectively being able to see what someone else is doing.

A manager at one of the sites I administrate has told another end user he can see what she is doing via the above method. This is at the very least unethical. If i find out that he has been doing it I'm going to lock his Mac down so hard.

The short answer is "Yes and No".
The longer answer is that if the manager has admin access he would merely need to turn on Apple Remote Desktop then VNC into that Mac. Set the VNC client to connect in "stealth" mode so the user wasn't aware.
But this is generic to VNC client/servers, not specific to the iSight camera. There is nothing that I know of that would allow the specific function of remote control of an iSight.
Of course the end user could place a sticky note over the camera...!